2008 President · IA
Mason-Dixon Polling & Strategy · fieldwork ended 2008-10-22 (13 days before the election) · 625 respondents · Live Phone
The poll said
Democrat 51% · Republican 40%
D+11.0
The certified result
Democrat 53.93% · Republican 44.39%
D+9.5
The arithmetic
- Poll margin = 51 − 40 = 11.00
- Actual margin = 53.928 − 44.393 = 9.535
- Signed miss = 11.00 − (9.535) = 1.465
- Absolute miss = |1.465| = 1.465
The poll overstated the Democrat by 1.5 points and had the right leader.
Where these numbers come from
Poll and result: 538 raw_polls.csv. Poll ID 16695, race ID 716 (538 database).